Paradigm Shift
by Sir Arghs III
Summary: Osamu Yasuhara believed himself to be a talented detective: he can study a case from different angles and can formulate a conclusion that is consistent with all evidence and accounted for by valid statements. However, it seems that there is one case that he cannot solve. Or, perhaps, that he is afraid to solve.
1. Prologue

"Mai. Tea." The voice of Kazuya Shibuya drifted from his office.

"Okay! Tea for everyone, too, except for Bou-san?" Mai Taniyama looked expectantly at the others.

The Irregulars, the part-time receptionist, and the Taoist priest slowly nodded as she hurried to the kitchenette.

The light banters that the black-suited president and his assistant exchanged at least ten times a day was a daily routine and was considered a trademark of the company. It was therefore painfully obvious and undeniably unnerving when the provoke-and-retaliate interactions stopped, such that the rest of the team shot each other baffled and explanation-demanding looks, to which everyone else responded with a confused shrug.

"Oi. What's happening here?" Houshou Takigawa leaned in and whispered. "Jou-chan didn't even complain." Koujo Lin hovered behind him.

"Maybe Mai-san was simply in a good mood today?" John Brown suggested, unconvinced.

"Maybe Mai finally gave up on Naru." Masako Hara whispered behind her kimono sleeve.

Ayako Matsuzaki scoffed at the last statement. "Dream on, Masako. Mai's not one to give up easily, you know?" The psychic medium huffed in reply.

"Maybe…" Everyone eyed Osamu Yasuhara, and he continued in a low voice, "Maybe it's a case we have to investigate?" They all looked at each other with new purpose.

"You're right, shounen. Okay. Ayako and Masako will confront Mai about it." Takigawa pointed to the shrine maiden seated on his left and the celebrity medium sitting in front of him across the table. "John, shounen, we observe the two and see what happens next." The two young men nodded. "Lin." He turned to the Taoist priest behind him.

Lin nodded. "I understand. I will observe Naru."

"That'll be a great help."

The part-time receptionist smiled. They had not received interesting requests for some weeks now, and it was about time they started working on a case.

"What're you guys talking about? Did someone finally bring us a request?" The unaware client handed them their drinks then headed for the president's office to hand the president his.

"Nah, it's an easy case. Not everyone's needed," the monk attempted at nonchalance. She hummed as her attention moved to her fellow part-timer. "Oh, right, Yasu, I left a reference book at your place."

"Ah, I'll give it to you tomorrow."

* * *

Osamu Yasuhara believed that solving this particular case was a group task, and he took it for granted that the group included him. But the next afternoon, his claim was harshly invalidated.

"My, everyone, why do you look like you saw a dirty old man?" He greeted the severe looks of most of the Irregulars and the blank look of Lin-san.

"Oh, I don't know, sweetie. Maybe because you are?" Matsuzaki-san retorted.

"And what does that make you, Ayako?" Takigawa-san risked. A purse came flying in response.

"Is Mai here yet?" The receptionist asked as he placed his bag under his desk. The others reluctantly shook their heads. "Great! Matsuzaki-san, Hara-san, have either of you talked to her already?" His eyes sparkled in interest. "What did she say? Had she and Big Boss finally reached a new stage?"

When silence ensued and everyone, even Lin-san, looked everywhere but his direction, his mind instantaneously reached a groundless but obviously valid conclusion. His spectacles reflected the setting sun as he adjusted them. Something drastic had happened. They all knew what it was. And they were not planning on telling him outright.

"I see."

He had to hold his own investigation.

* * *

 **Disclaimer:** I don't own Ghost Hunt or any of its characters.


	2. Witness 1: Masako Hara

A capable detective knows and follows certain steps in investigating a mystery. First, he must collect facts, pieces of evidence, and witness statements for his preliminary investigation. Then, he inspects his data collection more thoroughly and checks their validity. With every piece of information confirmed as true, one building brick is added to support the conclusion he meticulously constructs. He further develops his theory as he fits every brick perfectly, and his deduction is completed when facts that back up every claim in his reasoning cement everything together into a cohesive and logical explanation.

However, Osamu did not have many of those fundamental requirements to start forming any theory at all. And although evidence can be easily gathered through observation, he lacked witness accounts, which he considered just as important as evidence. It had been two days since he began his solo investigation, but he was still practically at square one. He needed to start gathering witness statements in order to proceed.

From where he sat at his desk, he looked at Hara-san, the only other person present in the reception area. Detectives always took risks, and he was a detective.

"Hara-san—" he began and never finished.

"No, Yasuhara-san, I will not entertain your questions." The psychic medium covered her lips with a sleeve.

"Ah, you saw right through me." He smiled and raised his hands in submission.

"…What do you want?" He could almost hear the huff in her prim voice.

"Just a listening friend, Hara-san." He moved to sit on the settee across her. "You see, I've been noticing many changes between Mai and Big Boss, and I wanted to discuss them with someone." Hara-san met his eyes; he got her attention. "You see, I always see their slightly vitriolic interactions as part of the core of the team's dynamics. When their bickering stopped, I observed closely how the change affected them and their interaction with the other members.

"First, Mai seemed to spend less time lingering around Big Boss when she gave him his tea. Strangely enough, she was never upset by having to spend less time with him—actually, she acted normal, if not more cheerful than before.

"Second, Big Boss's provocative remarks decreased remarkably. He still treated—or pretended to do so—her rather coldly but much less harshly now. But there didn't seem to be much change in their relations with others." He glanced at the medium: she was pensive. He continued talking to keep her engaged and thinking.

"Lastly, it seems that Mai had been going out at night more often."

"How do you know this?" She gave him a sharp look.

"Well," he replied lightly, "she kept holding off her turn to treat me to dinner. But that's not the point here, Hara-san. The fact that the way they treated each other changed while their interactions with the rest of the team did not implies that something happened and that whatever it was, it involved the two of them exclusively and deeply. I believe that their actions, therefore, can be interpreted this way: Mai and Big Boss may have decided to meet each other outside the office and after office hours." He concluded, as he restrained the excitement that threatened to be heard in his voice. "It's possible, Hara-san."

She studied him before asking quietly, "Yasuhara-san. Do you really think that?"

"Indeed, Hara-san. But I'm more interested in what you think of this."

The psychic medium released a long sigh, an action she was not known to do. "Yasuhara-san, when Mai was studying for college entrance exams, why did you start helping her?"

"I'm sorry?" he returned.

She repeated, "Why did you start helping her?"

* * *

 _He did not need to use his little gray cells to deduce that Taniyama-san was thinking about their boss again. He stared back at the brown-eyed girl staring at him. "Stop thinking of Big Boss, Taniyama-san. He might get shivers," he scolded._

" _Wha—huh?" The girl sputtered. "I-I'm not thinking about him at all!" Her face flushed with her outburst, and with her outburst came sheets of paper scattering._

 _He grinned knowingly. "Yes, you are~"_

 _Taniyama-san's red face grimaced, a sign for him to get them back on track. He motioned toward the fallen sheets of paper. She nodded, comprehending._

 _She pointed at a mathematical problem shortly. "Yasuhara-san, how do you answer this problem?"_

 _He leaned forward to assess the question. "Ah… for problems like this, it's better if you remember the trigonometric ratios or symmetric points. In this problem," he began writing on her notebook, "it's easier if you first find the coordinates of point A or point C so you could solve for the position of the inscribed hexagon's vertices." Taniyama-san watched as he solved the first part of the problem. Then, he repositioned the notebook before her. "Then you can solve the vector components. The minimum value of the vector's magnitude—"_

" _I can get it from the second-degree function in_ t _, right?" she asked enthusiastically. He smiled; despite what Big Boss said about her intelligence, she was a smart girl. As she solved the rest of the problem, he hoped she gets accepted in the universities she applied to._

* * *

"…Because she wanted to go to college, and she needed to pass the entrance exams to do so." His reply came after a long, retrospective pause.

"Mai could have asked Naru, Yasuhara-san."

"At that time, Big Boss was preoccupied with a major case involving the BSPR. Besides," Osamu pushed his spectacles up his nasal bridge. "Mai didn't like asking for his help in such a trivial thing."

"It is not a trivial thing at all." Hara-san's voice was reduced to an acidic whisper. "It involved her future. But instead of relying on her best choice, she chose you. Why you, Yasuhara-san?"

He flashed his default youthful smile. "Of course, because I have a wonderful personality, Hara-san."

"Exactly." She stood up and prepared to leave. "Though why she thinks of you that way eludes me."

The door closed silently behind her, and he was left alone again. He sighed in mild exasperation. He did get to talk to Hara-san, but what they discussed did not add any insight to his investigation.

* * *

 **Disclaimer:** I don't own Ghost Hunt or any of its characters. Neither do I own the sample problem; it was obtained from Mathematical Association of America.


	3. Witness 2: Koujo Lin

He knocked on the door to Lin-san's office and entered. "Lin-san, here's the file on the latest case." He handed the Taoist priest a black folder.

"I believe it was Taniyama-san who was assigned to organize this file. Was I mistaken?" Lin-san asked.

"Ah, no. Mai told me she was running a bit late today, so she passed it to me." Osamu was on his way to the door when he noticed that the older man had stopped typing and started studying him. "Is there something wrong, Lin-san?" he asked accommodatingly.

"Nothing. Just that… you have maintained quite a close relationship with Taniyama-san these past few years."

He simply nodded. "Indeed."

Lin-san swiveled his computer chair to face him fully. "Taniyama-san and Takigawa-san are the only ones who address you with a nickname."

"You're right," he affirmed yet again. This was the first time the older man initiated a conversation with him, and since he can barely read the man, Osamu did not know whether to feel honored or wary of this development.

"But only Taniyama-san is addressed by first name." Lin-san's question was more of a statement.

"Ah…

* * *

 _His phone rang just after he got out of the bath._

" _Yasuhara-san! I'm so glad you're still awake!" Taniyama-san exclaimed. He could hear the excitement in her breathless voice, and he grinned proudly as he expected her to break the good news. "I passed, Yasuhara-san! I wanted you to be the first to know, as thanks for tutoring me." Then, she added shyly after an audible inhalation, "By the way, Yasuhara-san, when are you free? I want to treat you to lunch or dinner."_

 _From her hesitation, he surmised that she was on a tight budget, so he smoothly offered an alternative. "I say I call Takigawa-san and the others, ask them to bring food, and we all celebrate at the office tomorrow. What do you think?"_

"… _Y-Yeah! Sounds great, ehehe…" she replied after a slight pause._

" _Are you scared of Big Boss lashing out at us?" He almost chuckled. He did not think that their boss could stop her—if Big Boss had a weakness here in Japan, it was definitely her, though he was unsure whether the bright, promising girl was aware of that fact. "I believe you can handle him just fine. Maybe if you showed up in—"_

" _I won't even let you finish!" she screeched. "Yasuhara-san, for someone so polite you sure talk like… like…" She giggled and whispered, "Like a dirty old man."_

 _He gasped. "That's—! That's my secret, Taniyama-san! Please don't tell anyone else. What would they say about me if they heard I'm a two hundred-forty-four-year-old dirty old man?" He finished passionately._

 _She laughed heartily before managing to choke out, "Yasu-Yasuhara-s-san!"_

" _And since I'm an old man, you should listen to what I say. We celebrate in the office, all right, Taniyama-san?"_

" _Okay, Yasu." He could hear the smile in her voice._

"… _Pardon?" All his life, he was officially called only three names: Osamu, Yasuhara, and Echigoya. Yasu was not one of them. But he was surprised to realize that he did not dislike the addition to his humble collection._

" _Oh, sorry. You don't like it?" He heard the disappointment in his former tutee's voice._

" _No, it's not that," he assured her. "I was just thinking of what I should call you."_

" _You could always call me Ma—"_

" _Mahou Shoujo."_

"— _huh?"_

" _Because you're simply magical, Taniyama-san."_

"… _Are you hitting on me, Yasu?" Her voice was now incredulous._

 _His lips, unseen by anyone, curled up playfully. "Maybe?"_

" _I-I'm telling Bou-san on you!" she answered, sounding flustered._

" _Shush. It's our secret, Mai." He made sure she heard his wink through his voice._

* * *

"Yes," he answered, hopefully for the last time.

"I see. Thank you for submitting the file." The older man offered a small, brief smile and returned to his typing duties. The younger one returned a wider smile and exited the room.

Osamu was well aware that he had a way with people. He gleaned all that he needed to know by observing people and interacting with them in ways that stimulated the most reaction. But only recently had he realized that there existed individuals who could grow immune to his smooth talking and his persuasive sincerity. Everyone in the SPR team, save for Mai, constituted that rare group. But since Osamu was never able to completely read him, much less to get a reaction out of him, Lin-san was different. He was an outlier, and Osamu, who rarely conceded to anything or anyone, had long ago given up on even trying to interview him.

He needed to talk with someone else, someone less unapproachable.

* * *

 **Author's Notes:** Hi! Thank you for reading, faving, following, and reviewing _Paradigm Shift_. :D If any of you have read my other fics, you'll see that this one is different in many ways. This fic was the first one I ever wrote for Ghost Hunt, dedicated to my sister, who acted as my sounding board when I conceived its beginnings. I still dedicate this to her, and now I'm dedicating it to you as well, dear readers. I hope that you'll stay with Yasu as he continues his investigation. :3

To _soulsborne123_ : Thanks for staying interested! I was wondering whether someone would see through the title after reading just the prologue, or if it will take the first chapter to seal the deal, but you caught on right away! Well done! :D Can you guess who the next witness would be?

To _ghost44_ and anonymous reviewer _MoooooorreeEeEeE_ : Thanks for reviewing! I'll be uploading the chapters quite quickly, so please stay tuned. :)

To _Agwen_ : Thanks so much for your kind review! You're right; and out of thousands of fics under Ghost Hunt, I think there are only around 5 with a YasuxMai pairing. I find it a bit unusual that the pairing is so obscure despite their chemistry even as friends, but maybe I'm as biased as you are because I absolutely love Yasu, too! XD

 **Disclaimer:** I don't own Ghost Hunt or any of its characters.


	4. Witness 3: Houshou Takigawa

If Osamu were to rely on anybody's rationality, it had got to be on Takigawa-san's. Takigawa-san was the smartest one in the group after Big Boss, after all. He was always the one who caught on to the SPR president's theories and was the one who uncovered Big Boss's true identity and exposed it before everyone. And he was just the person Osamu needed at this point.

He had just resolved to convince the monk to discuss this case openly and directly when the man himself entered the office.

"Oh, shounen, you're here. Good."

Osamu beamed. "Very good, indeed."

Takigawa-san checked his watch. "You free? Let's get lunch, my treat."

"My, Takigawa-san~"

"I'm having none of that today, you hear me, shounen?" The monk replied wearily.

They headed for the door.

ooo

After ordering their meals, Osamu crossed his forearms on the table and leaned forward. "I've been meaning to talk to you, Takigawa-san."

"Me, too. But I'm afraid I'll be the one doing most of the talking here. So you have to listen carefully, shounen." The monk's face was serious. The young man waited for him to continue. "You've been trying to find out what happened between Mai and Naru-chan yourself, haven't you? What've you learned so far?"

"Well, not much… I've only spoken with Hara-san on the matter." Osamu shook his head. "But I didn't really get anything out of her other than she dislikes me more now."

Takigawa-san studied him. Osamu smiled wryly; it seemed that he was being studied quite often in the last few days. "I heard about it. But I don't think what she told you was completely unhelpful in your investigation."

"What do you mean?"

"Exactly what I said. Look, shounen. You're looking at this whole thing from the wrong angle. No—I'm pretty sure you'd already gotten a grasp of what all this is about, just that when you realized where it was going you may have automatically and subconsciously dismissed it as impossible. So you resorted to thinking from the wrong but more comfortable perspective." Takigawa-san gave the young man a look full of meaning, but silent incomprehension was the only response. The older man sighed. "As I thought. You're not aware of it at all. Let's try this again. I want you to recall Mai's graduation day."

* * *

" _That idiotic, mad scientist!" Mai stomped her foot on the ground. She was wearing her full high school uniform for the last time. "To choose this day of all days to return to England!" She sighed as she sat on a bench._

" _Now, now, Mai. I'm sure he was forcibly summoned. He would never miss his assistant's graduation now, would he? Don't be so upset." Osamu rummaged through his bag until he found a piece of treat. "Here, have some Mahou Shoujo candy." Mai pinked like the early blooming cherry blossoms._

" _Two things, Yasu: one, I'm not a Mahou Shoujo—argh!" She groaned as he winked playfully. "And two, I'm not that upset, just… a bit pooped. Besides, why would I ruin everyone's mood when you all made time to attend my graduation? Those who chose to be here with me are more important than those who didn't." She beamed at everyone. They all returned smiles just as bright and lined with pride._

" _Aww, c'mere, jou-chan!" Takigawa-san burst in fatherly happiness and wrapped an arm around Mai's neck; the other arm he used to ruffle her hair. The captive girl complained insincerely as Matsuzaki-san scolded the monk for his childishness._

" _Mai." Hara-san, clad in her trademark kimono, called. Mai, still wrapped in fatherly love, turned to her. "Since I attended your graduation, I... expect you to attend mine." She covered her face with the edge of her sleeve. Everyone realized the implication of this gesture, and the merry mood continued as they made their way to the restaurant they reserved._

" _Mai-san, I don't believe ya've told us which university ya're going to." Brown-san commented._

" _Yeah, Mai. What, was it supposed to be a secret until you're officially admitted? Are you going to wait until you realize you're not fully prepared yet and you need us to rescue you before you tell us, huh?" Matsuzaki-san pointed a long-nailed finger at the subject of her worry and target of her nagging. "Huh?"_

 _Mai shrank from everyone's expectant stare but kept her lips pursed._

" _Jou-chan…" The monk's eyebrows approached each other._

" _Mai." The psychic medium's voice was dry and icy._

" _Mai-san?" The priest asked worriedly._

" _Taniyama-san." To everyone's surprise, even the Taoist priest spoke._

 _Mai stood frozen in a spotlight, and Osamu shuddered for her. But as always, he had a quick get-away tactic to save her._

" _Now, now, everyone, surely Mai just didn't want to tell us before it becomes official. She didn't want to jinx—"_

" _It's Todai." The now red-faced girl surrendered. "I'm studying Psychology."_

 _All the SPR subordinates cried in pleasant surprise and admiration—all but Osamu. It was his turn to freeze._

* * *

"Did you do it?"

Osamu nodded thoughtfully. "What about Mai's graduation?"

"I noticed some very strange reactions from you and Mai that day."

"Strange?"

"Hey, I'm doing the talking today, remember?" Takigawa-san said in slight impatience; Osamu smiled sheepishly in apology. "The first was after her graduation rites, when we told her Naru was called back to England that same day. Shounen, what's with Mai being a Mahou Shoujo?"

The younger man laughed lightheartedly. "It was an inside joke, Takigawa-san, nothing else."

"Inside joke, huh…" A waiter arrived with the food they had ordered. "When she finally told us which uni she was going to, I distinctly remember how you froze for almost thirty seconds."

"To remember what I did that day so clearly… You must really like me, Takigawa-san."

"Shounen…" the long-haired monk grunted but persisted, "You should've been excited that she was going to the same uni you attend. Instead you were awfully shocked. _Awfully._ "

"Why, I was just surprised. When I was tutoring her for the admission tests, I used reviewers for the Todai entrance exams. So when she said she got into Todai, I thought it was a good decision to have done so."

"Was that really all?"

"Yes. Was there supposed to be something else?"

"Was there nothing else?"

"…None?"

Takigawa-san sighed again and leaned back. "I really wish I could just tell you everything outright, but I want you to realize everything yourself, shounen. It doesn't seem to be enough, but this is all I can do to help right now. Talk to Ayako. She might knock some sense into you."

After a contemplative pause, the younger man replied slowly, "You mean her purse will."

Takigawa-san guffawed.

ooo

On the way back to the office, Osamu walked in silent meditation. The conversation did not go in the direction Osamu intended for it to go. After all, he, the investigator, ended up being the one questioned. Furthermore, the monk mentioned help. What was he helping with? And why did he think the younger man needed help? Osamu had always been the one on the helping end, so the idea of being helped, especially in something unknown to him, caused a slight discomfort.

* * *

 **Author's Notes:** Finally, some Bou-san screen time!

To _Agwen_ : I just had to include that part! I think Yasu is too much of a smooth operator to pass up the chance for a pick-up line. XD I just read "Making It Easy". I loved it! If I hadn't known it was Yasu/Mai, I would've been torn between cheering for Yasu or hoping for Naru to change. But in the end, after everything she had to put up with (because of grumpy Naru), Mai deserved to be happy, and I'm very happy with the ending. :)

To anonymous reviewer _Nix_ : Thanks for reviewing! I hope you'll like the next chapters, too. :D

 **Disclaimer:** I don't own Ghost Hunt or any of its characters.


	5. Witness 4: Ayako Matsuzaki

"So even _that_ Bou-san wasn't any help, huh." Matsuzaki-san was amused. "That's not good."

They were in a café within the vicinity of the Matsuzaki General Hospital. It was just a little bit after regular office hours, so the doctor still donned her white coat. Osamu watched the rush of employees outside the shop window.

"So? What do you want me to do?"

He turned to her. "Takigawa-san suggested that I talk with you, Matsuzaki-san."

"He finally realized that I'm better than him. Hah!" She cackled. Then, she placed her elbows on the table and cupped the side of her cheeks with her hands. "Okay, then.

"Let's start: what do you think of Mai?"

Osamu grinned. "She's my best friend, and needless to say, I'd do anything for her."

Matsuzaki-san considered what he had just said. "Even best friends have something they won't be able to do for the other, sweetie."

"Then I guess I transcend that kind of best friend," he replied proudly.

"Oh? So you're willing to buy her sanitary napkins when she's on her period and can't move?" she challenged rather childishly. He raised an eyebrow.

"My, Matsuzaki-san, that's quite the pretty example. But yes, I'm willing to."

"You'll leave in the middle of an important business meeting when she's about to give birth alone?"

He snorted.

* * *

" _Mai?" he called out from outside the door. He had been knocking for a few minutes now, but the girl who had sent him a distressed call half an hour ago was not responding. "Mai, if you don't answer in one minute I'm calling the emergency hotline and telling them you're about to give birth." He was knocking again when an idea occurred to him. He coughed a little to change his voice to that of a worried husband. "Darling, are you okay? Can you stand? Did your water break already?" He gasped theatrically. "HONEY, ARE YOU GIVING BIR—"_

 _In one swift movement, the door opened and he was roughly pulled into her apartment._

" _What were you_ thinking _, Yasu?!" she fumed. "Stop causing trouble for me! I already have enough as it is!"_

 _He needed only to lay his eyes on five regions of the apartment to determine ninety-nine out of the hundred problems she had: the low table scattered with handouts, notebook fillers, and open books in front of him; the electric fan blowing hot wind under an air conditioner that was not blowing any beyond the table; the dining table with an empty teacup used as a paperweight for more handouts and fillers with pink post-its to his right; the made-up futon that had not been slept in for one—two, maybe three nights, seen through the open bedroom door to his left; and the source of his worry, whose hair was unwashed for the day and was as frazzled as its owner's nerves, just beside him._

" _Ah." He nodded empathetically. "Your first finals."_

" _Yasu, what do I do?" The poor young woman almost shouted in panic. "I think I picked the wrong school! I should've gone to Waseda instead! I'm gonna fail, Yasu—I can't believe I paid for a semester I'll end up failing! I—"_

 _He embraced her tightly to shut her up. Yes, the first finals in the university was one of the most anxiety-inducing events of a Todai undergraduate, and every student had developed a coping mechanism just to survive it. But the one Mai developed was definitely not effective. It exhausted and slowly destroyed her, and she needed to calm down and recharge._

 _He felt the tension in her shoulders lift as she returned the embrace. "What's this?" she asked, mirth replacing the fury in her voice. "Is this some kind of intelligence osmosis or something?"_

 _He chuckled. "I was thinking more along the lines of recharging your life battery with my electric personality."_

 _She finally laughed. "You really believe in your stellar personality, huh?"_

" _It's almost my religion." He held her a moment longer before letting go. Turning her toward the god-forsaken and Mai-forsaken apartment, he barked, "Taniyama!"_

" _Yessir!" she saluted, still facing her quarters._

" _Pack your notes, your books, and clothes good for two days!"_

" _Ye—huh? Why?" The perplexed young woman turned back to him._

 _His spectacles gleamed in the ceiling light as he readjusted them on his nose. "Because, corporal, we're going to a training camp, and you're going to learn how to survive your first finals." Mai gasped._

" _Yasu! I love you!" She threw herself at him; he caught her effortlessly, naturally._

" _But first, you need a shower, yes?"_

 _ooo_

 _When Matsuzaki-san arrived at his apartment the following day and saw Mai sleeping on the couch, she clucked at him. "Yasuhara-kun, you're a young man. Mai—" she pointed at the blanketed bundle sleeping peacefully, "—is a young woman. And what's a young man to do when he lets a young woman into his home?"_

 _He parted his lips to answer, but the shrine maiden held up a well-maintained hand._

" _On second thought, I don't want you to answer that."_

" _Then what should I have done, Matsuzaki-san?" he asked with a mischievous grin._

 _The doctor merely stared at him. "It's obvious, sweetie. You should've relinquished your bed and slept on the sofa instead."_

" _Ah."_

* * *

"Naturally."

"And when you're both old you'll give her your cane when she loses hers?"

"Sure."

She hummed. "You're saying you'll be there for her until you both grow old?"

"The greatest friendships last a lifetime."

"And you're confident your relationship won't change?"

"Yes."

"So you'll hand her over to Naru willingly?"

"—What?" Osamu narrowed his eyes.

Matsuzaki-san simply checked her filed, painted nails. "I don't like repeating myself, sweetie."

He laughed disbelievingly. "Matsuzaki-san, you're joking, right? Mai's been Big Boss's right from the very beginning; they only needed to get it on and make it official."

Her eyes moved to focus on his. "Well."

"Well?"

"Well."

"…Please just tell me what you're all hiding from me, Matsuzaki-san."

"We're not hiding it at all. You're the one who refuses to see it."

"It's because I can't seem to see it."

"Oh, believe me, sweetie. You _refuse_ to see it."

He smiled an almost irritated smile. "I can't, Matsuzaki-san, because I _don't_ see it."

But her smile had more edge. "Yasuhara-kun, I hope to the heavens that you're grateful I didn't bring my purse."

"Now, now, Matsuzaki-san…" he said in a placating tone.

The doctor huffed before drinking her tea. "Then let's continue. What, in your opinion, does Mai think of you?"

"I'm the best friend she could ever have." Osamu's spectacles sparkled as he posed like a salesman on TV advertising his product.

"Do you think she'd do anything for you, too?"

"Let's see… there _are_ some things Mai can't do…"

"Do you think she'll leave Naru for you?"

"Ah, you're joking again."

Matsuzaki-san sighed. "…I never thought I'd have the need to say this to you, Yasuhara-kun, but…" She stood up, pointed a finger at him, and shouted, "You're an idiot!" She turned to leave, ignoring the heads that had turned in her direction. "Talk to me again only after you've regained your detective skills," she added, waving a hand behind her.

He stared at the doctor's retreating figure. Not for the first or the second time, Osamu's plan to gather witness statements for his investigation was hampered, and he was left alone in bemusement.

* * *

 **Author's Notes:** [Edited 01-21-17] I corrected how Ayako addresses Yasu for consistency with the anime/manga/novel, and I'll be doing the same for the rest of my works. :) Many thanks to _Agwen_ for clearing it up!:D

To _Agwen_ : She did! :D Maybe for Yasu it was surprising because as you said, there are many unis in Tokyo. But well, we all know why she chose Todai! XD I've always thought Mai would pursue higher education if she could. And that, since she wanted to help both the living and the spirits to find peace, she would want to study how the mind works to try to understand a person/spirit's motivations and guide them accordingly. I think Psychology fits her quite well. :) BA Psychology is under the Faculty of Letters in Todai.

To _soulsborne123_ : *sigh* Yasu, please. Maybe John would do a better job? XD

 **Disclaimer:** I don't own Ghost Hunt or any of its characters.


	6. Witness 5: John Brown

"Yasuhara-san, yar shift is almost done, isn't it?"

He looked up at the blonde-haired man sitting on the reception settee. "That's right, Brown-san. Is something the matter?"

"Ah, nothing, but… Would ya like to accompany me for a walk?" The priest invited with a smile.

"Of course." Osamu smiled back; it was impossible to begrudge the kindly man a smile. "Please wait a moment." He logged out of his laptop, checked the time, and logged it under the OUT column beside his name in the record book. "Mai," he called out.

"Yeah?" came from the kitchenette.

"I'll be going ahead. Big Boss and Lin-san seem busy, so tell them for me, please."

"Sure! Good work today. See you tomorrow!"

He turned to the priest. "Shall we, Brown-san?"

"Ah, yes."

ooo

"Let's sit here, Yasuhara-san." Brown-san motioned to a table concealed from the more public area of the park.

"Ah, this table!" Osamu chuckled in recognition as they sat across each other. The sun had set about an hour past, and lampposts had become the park's source of light. There were less visitors now, mostly couples and the elderly walking at leisurely paces. Children had long stopped playing and been fetched by their parents, so it was more or less silent.

The priest smiled. "Yes. It brings back memories, don't ya think?" he said quietly.

"Indeed."

The two remained in reminiscent silence for a long moment.

* * *

 _The chimes rang when the door opened, and the room considerably brightened as Mai entered the office._

" _Good morning, Yasu, Naru, Lin-san—oh, everyone's here!" She dropped her bag onto her chair before heading for the kitchenette. "Tea for everyone and iced coffee for Bou-san?" She asked without expecting an answer, when she should have._

" _Jou-chan… what are you doing?" Takigawa-san walked in after her. "We're all going somewhere. That includes Naru-bou, and that includes you." The monk reached for Mai's hand and led her from the kitchenette to where everyone was staring impatiently at her._

" _So," she laughed nervously, "where're we going?" No one stirred._

" _Mai." Big Boss stood just outside his office door, his arms crossed and his back leaning on the door frame. "You're an idiot, aren't you," he stated._

 _Her mood changed from chipper to livid in two seconds, approximately. Osamu watched her clench her fists as she mustered all the best insults and comebacks she could think of. Even before the oncoming storm that was an angry Mai, he gave in to his urge to grace the SPR president with an appreciative and admiring smile. Only one person in the whole world could make the cheerful part-time investigator feel emotions so intense that all her reactions to other people seemed stoic. The admiration twisted into something else—but he stopped himself. Big Boss's talent of getting her riled up violently was commendable and all, but the rage he incited was not what they all had in mind today. After all, today was a special day. Osamu decided to defuse the ticking Mai-bomb._

" _Mai-san, have ya tasted sake before?" Brown-san beat him to it._

 _Mai turned to the priest in confusion. "Eh? No, I'm not legal—" She clammed up and ran to her desk to check the calendar. Then, she smiled sheepishly. "Ehehe…"_

 _Matsuzaki-san sighed. "Now that you remembered, let's get going before Naru and Lin-san get tempted by their work again."_

 _The birthday girl flashed her superior investigator and their boss a grateful smile. "Thanks, everyone!"_

 _ooo_

 _Osamu ensured that everyone in the SPR team attended the birthday celebration for two reasons: first, he wanted Mai to be able to share her happiness of being alive with everyone, and second, he wanted everyone to be witnesses to her first taste of alcohol. So he asked each one in the team to bring a different kind of alcohol for the lucky birthday girl to try._

" _Now, for the main event!" He clapped his hands with the enthusiasm of a talk show host. They were now occupying an obscured table in a nearby park, with Mai seated at the middle of one side's bench. She gulped, and he knew that she knew that it was he who planned all of this. He saw her brace herself. "It's time for Mai's first taste of alcohol!"_

" _Alcohol?" Mai laughed nervously for the second time that day. "You mean just sake, right?"_

 _Everyone smirked—or tried very hard not to, like Brown-san._

" _Don't be a spoilsport now, sweetie~" Matsuzaki-san coaxed. "We all brought drinks we thought you should taste. Right?" She smiled at Osamu, who smiled back._

" _Indeed, Matsuzaki-san. But you're going to be the last, unfortunately."_

" _Tsk."_

" _I guess I'll go first, then." Takigawa-san stood up from Mai's right and presented his beverage. "To jou-chan, I present sake!" He poured some on an ochoko, which he handed to Mai. He filled another ceramic cup and then raised it toward her. "Happy twentieth birthday, Mai!" She raised her cup in response. Then, they downed the sake in one fell swoop._

 _Mai held out her tongue disgustedly. "I'm never drinking sake again."_

 _Big Boss, who sat across her, stood up next and handed her one of two pre-prepared glasses of a fruit cocktail._

 _The birthday girl sniffed at the glass filled with sliced orange and yellow-brown liquid. "What's this?"_

"— _Pimm's cocktail." He said simply, raising his glass in a toast. The boss and his assistant both drank._

" _Oh. It's not as bad-tasting as sake," she commented, surprised. "No, it actually tastes good! Naru! Do you have more?"_

 _But the boss just smirked as he took his seat again._

" _I'm next, Mai-san." Brown-san brought out two cans. Mai watched as he opened the tabs._

" _I didn't know priests were allowed to drink," she said when he handed her a can._

 _John smiled sheepishly. "Not all priests are prohibited from drinking spirits…"_

 _Bou-san grinned and whispered, not so silently, "You should see him_ drink _, Mai. Well, now that you're twenty, you can come with us."_

" _I-In any case!" John interjected. "Happy birthday, Mai-san." They clinked their cans and drank._

" _Wow, if only all beers tasted like this…" she sighed contentedly, and the priest chuckled. "Okay, I think I'm still not drunk. Who's next?" She put her just emptied can aside to make way for the next one._

" _I hope you can still say that after you drink my present." Hara-san stated primly but haughtily. "Since I am still nineteen, you will have to drink this alone, Mai." She offered the bottle to her rival in love._

" _Ah, Hara-san, that won't do." Osamu shook his head disapprovingly. "The birthday girl shouldn't drink by herself on her big day."_

" _Are you suggesting I drink the plum wine, too, Yasuhara-san?" she challenged._

" _Not at all! What I'm suggesting is simply that you give Mai a toast, and I drink it for you." He flashed his bright, youthful smile._

" _My, you are quite the eager one," she replied a bit distastefully._

 _His smile widened._

" _Very well." She poured the wine into two pottery cups, handed one to Mai, and raised the other in salute to her rival and friend. "Happy birthday, Mai." Hara-san then gave him the cup, which he drank just as Mai did._

" _It's… not so bad." Mai slowly lowered her cup. "Thanks, Masako." She smiled victoriously at Osamu. "Hey, Yasu, I could do this all day!"_

 _His glasses glinted in the afternoon sun. "Why, Taniyama-san, I believe we're only halfway through." He stood up and presented his drink. "Mai, I'd like to introduce you to shochu." He procured two glasses, to which Mai visibly paled, and filled them to the brim. He gave her one and tapped his overflowing glass against hers. "Enjoy." They finished their drinks at the same time. Mai reeled; Osamu just_ grinned _._

" _Here, Mai. Drink water first." Matsuzaki-san, the doctor, gave the celebrant a glass of cold water. "Jeez, why did you match this guy's—" she reached out in front of her to knock on his head, "—pace? He's an expert, unlike you." When Mai finished drinking, she asked, "Feeling better, sweetie?" The birthday girl nodded with a flushed face._

 _Lin-san, after confirming his fellow investigator's well-being, stood up. He proffered a small smile together with a shot glass of white liquor, then raised a matching glass in her honor. "Happy birthday, Taniyama-san." She bowed her head shyly; they drank._

 _And then, Mai banged her glass on the table in a violently brusque way. "Hey, Lin-san? Are you kidding me? ARE you kidding me?" The doctor, who was sitting beside her, began to appease her with water. "No, no Ayako you don't understand. This is awesome. Lin-san, this…" she motioned to the bottle of drink, "is the_ illest _thing. What do you call this drink for the gods—this… this… what's the word? Oh!_ Ambrosia _?"_

 _A shocked silence ensued before Matsuzaki-san, Takigawa-san, and Osamu burst out cackling, guffawing, and heartily laughing, respectively. Hara-san was shaking in laughter behind her kimono sleeve, Brown-san was chuckling, Lin-san was silently laughing behind his fist, Naru was smiling amusedly, but Mai was confused and angry. A camera Osamu borrowed from SPR had been recording everything from the moment the monk presented his gift, and as the young receptionist glimpsed it, he was glad he risked borrowing it. He mentally patted himself on the back._

" _What's so funny? I feel_ immortal _, you know? I'll electrocute you with my Zeus powers!" she cried._

" _Or get us pregnant!" He countered, and everyone's mood rose ever so higher._

 _Mai's face reddened. "Huh? Will I get you pregnant, Yasu?" Matsuzaki-san and Takigawa-san were in tears._

" _I don't know. Will you?"_

" _I don't know either!" Mai was growing frustrated now. "I want more of the ambrosia! Yasu, offer some to me on bended knees. Treat me like a god!"_

" _Unfortunately, for today, you can only drink everything once." He wiped a tear off his eye. "It's Matsuzaki-san's turn now."_

 _Mai looked expectantly to her left, at the doctor who stood when called. Matsuzaki-san filled two shot glasses and slid one to the right. "Bacardi 151 to the most adorable drunk I've ever seen and to Yasuhara-kun who intricately plotted all this." She raised her glass toward Mai, while Mai struggled to lift her own. "Happy, happy birthday, sweetie." They downed their drinks swiftly and in sync. Then, Mai slurred to her right and fainted on Takigawa-san's shoulder. Matsuzaki-san's cackle was not unlike a witch's._

 _Osamu beamed at the laughing group. "Don't you think I'd make a perfect birthday planner?"_

* * *

"I have to admit, Yasuhara-san. It was a very entertaining celebration." Brown-san chuckled.

"Thanks!" Osamu grinned. "It's one of my masterpieces as a planner."

"Ya really do yar best for Mai-san."

"…She had experienced loss that most of us couldn't even begin to imagine, and yet she chose to continue doing everything in happiness and optimism. She deserves nothing less, don't you think?"

"Ya're right."

A calm hush fell upon the two again.

After a while, the priest spoke gently. "Yasuhara-san, do ya have feelings for Mai-san?"

Osamu laughed. "What's this, you're inviting me to go to confession?" he mildly teased. When the latter merely waited for his answer, he replied, "Mai's in love with Big Boss. He should be the one you're asking, Brown-san."

"…It's ya I'm asking."

"So this really is a confession."

"If ya want to think of this that way… then let's say it is."

A pause.

And then, "I'd be lying if I said I never did."

"Ya can be honest with me, Yasuhara-san," came the benevolent reply.

The younger man considered this solemnly. "…You said we could think of this as a confession, right?"

"Yes."

"Then…" He turned in his seat, so that his back now faced the priest. Staring at the trees that veiled the other side of the park, he uttered, "Father, forgive me for I've sinned. Is that how it should start?"

"Please go on." Brown-san's voice encouraged.

Osamu drew a deep breath. "I... have fallen in love with Mai. The girl who always did and stood by what she believed was right. The girl who never succumbed to the tragedies in her life and instead focused on the things she was blessed with. The young woman who considered others to be as important as she is to herself and thus treated all as her equals. The woman who fell in love when she was just a girl and had now learned how to love unconditionally. The woman for whom I could do anything.

"My best friend. Shibuya-san's—no, Oliver Davis's only emotional support."

Silence fell once more.

And neither made an effort to break it for an extended time.

Osamu felt a hand on his shoulder. "There's nothing for ya to be sorry for, Yasuhara-san."

Without turning, he replied with a ruefulness that escaped restraint, "Ah, that's where you're wrong, Brown-san. Because of what I've done, the probability of my ruining our friendship exponentially increased, which, as a consequence, will undoubtedly disrupt the harmonious professional and personal relations between and among us and Shibuya-san. The home she finally found will crumble at one very important wing—I have _everything_ to be sorry for."

"…There's nothing to be sorry for." Brown-san repeated before withdrawing his hand from the younger man's shoulder. A shuffling sound, and then: "I'll leave ya to yar thoughts now, Yasuhara-san. Thank ya for accompanying me." The priest's subdued footsteps persisted for a short while before slowly fading into the early night.

* * *

 **Author's Notes:** I corrected how Ayako addresses Yasu here and on the last chapter. It's minor, I know, but for me it makes the Ayako I write more like her, even if a little bit. :) Anyway! What do you guys think? John's perfect for his job as a priest, isn't he? XD Two more chapters left!

To _soulsborne123_ : Your wish is my command! :3

To anonymous reviewer _Anon_ : Rather than jealous of Mai's admission to Todai, Yasu was more surprised that she chose the same uni he goes to, out of all the choices she had. As for your questions, I hope this chapter adequately answered them. :) Thanks for reviewing!

To _Agwen_ : Yup, so far! :3 Thank you for clearing that up! It does make more sense for Ayako to call Yasu with a -kun than with a -san. I've read those shorts, but I'd totally overlooked Ayako's use of honorifics. :O OTL

To _Fanficluver4life_ : Thanks for giving this fic and this pairing a chance! Indeed, the potential (and confirmed canonicity) of NaruxMai is too great, but there's something about YasuxMai that, when you take time to think about it, just makes sense. :) If you're interested in other fics with this pairing, I suggest "The Little Moments" by _mysticflakes_ on this site and "Making It Easy" by _ginny_t_ on the shibuya_pr LiveJournal. "The Little Moments" was published around the time I finished writing my fic, and I was quite shocked to find it so similar to what I've written! Still, I loved it—you can even see my anonymous review as _cyaniderush_ in there! XD

 **Disclaimer:** I don't own Ghost Hunt or any of its characters.


	7. Witness 6: Oliver Davis

It had been more than a week since the routine banters of Big Boss and Mai suddenly stopped, and all Osamu was able to use in constructing the shaky foundations of his theory regarding this matter were the observations and the assumptions that he shared with Hara-san. He intended to gather the team's accounts to further build on his reasoning, but all he was granted were cryptic conversations, unfunny jokes, or invitations to admit things he never planned to. The turn of events so far had been wearing his lengthy patience very short.

So he tried to approach one of the two suspects in this case.

"Yasuhara-san." He and Mai were about to leave the office when Big Boss, holding a black file folder, called his attention. He grinned inwardly.

"Yes, Shibuya-san?"

"A moment please."

"Eh? Naru, we've already worked overtime!" Mai protested. Her superior merely gazed at her.

"Mai."

"Yeah, Naru?"

"Make some tea before you leave."

"Okay, just don't forget to eat dinner after," she easily surrendered with a sigh and then added to Osamu as she headed to the kitchenette, "Yasu, I'll see you later, alright? It's your turn to treat me to dinner!"

"Yup."

"Lin." Big Boss addressed the man who emerged from his office after the young woman's slight outburst. "You're free to go as well." Lin-san nodded and prepared his things.

ooo

After the tea had been served and the two office regulars had left, Big Boss sat on the lounge's settee. He motioned for his part-time receptionist to do the same.

"So…" the part-timer initiated.

The president held up the black folder. "I wanted to ask what evil spirit possessed you to submit a terrible case file."

"Ah." Osamu almost grinned. "I actually have the real one right…" He went to his desk to retrieve another black folder from one of the drawers. "…here." He proffered it. "I just wanted to get an opportunity to discuss some matters with you, Shibuya-san. Alone." He returned to his seat and stared at his chief. Big Boss's eyes were reduced to slits.

"And what would those be?"

"Matters about you and Mai."

"—I hardly think it's any of your business."

"You're right. But it's worrying everyone." The subordinate adjusted his spectacles. "I'm holding some sort of investigation, and I have a few things I'd like you to confirm, Shibuya-san."

The beautiful man sighed, then silently and gracefully brought the steaming cup of tea to his lips, a sign Osamu recognized as consent.

"Then let's get straight to the point. Did something happen between you two?"

"What made you think that?"

"About a week ago, the lighthearted bickering between you and Mai had suddenly stopped. This exchange of wisecracks, suffice to say, was a significant part of the whole team's dynamics. And to be honest, I consider it to be one of the special traits of this company and one of the things that endeared me to it. But it stopped." Osamu leaned forward. "What could've happened for something so habitual to do so?"

"Enlighten me, Sherlock," was the disingenuous reply.

"There are two possibilities that could cause such a drastic change in routine. The first possibility is that the need for it receded. The second is that a bilateral agreement to discontinue it was reached." Big Boss remained silent; he continued. "I believe it's the former."

"Because…?"

"Because your relationship seemed to have become much less turbulent ever since that day. So much so that until now I'm not sure which one I should find more startling: how just before the said day you were at each other's throats over your expressing gratitude when she serves you tea, or how the two of you remained cordial continuously for more than a week.

"It's a given that Mai reacts quite vehemently to just about all of your sardonic remarks and that consequently, you can't resist not teasing her with every chance you get. Quite the twisted _flirting_ , yes?" Osamu shrugged when he received a cold glare. "It's obvious, Shibuya-san. Moving on, why would two people, interested in each other, stop flirting publicly so suddenly? It must be because they could do it privately and totally without the sexual tension." He waggled his eyebrows. The glare intensified.

"Yasuhara-san."

"Shibuya-san."

"Is this some kind of joke?"

"Not at all."

"—You mean to say that you believe the stupid assumptions you just stated."

"Completely."

The president sighed exasperatedly. "Idiocy is very uncharacteristic of you, Yasuhara-san."

The subordinate reflected on this. "For you to say it's stupid… would you please clarify, Shibuya-san?"

Big Boss regarded him so intensely that Osamu thought the black-suited man would not give a response. But after an uncomfortable silence, it came. "It's stupid how you automatically discredited the second possibility, assumed the first to be true because you believed the other to be improbable, and jumped to your intended conclusion brainlessly. I expected much more from you."

"What… are you implying?"

"I think you can use your brain."

"…You're saying my reasoning is faulty, and that it's the second possibility that's correct?"

"So your brain still functions." The chief almost clapped his hands.

Osamu was too preoccupied to respond to the remark. "But—I don't understand. Why would you both agree to stop it?"

"—Mai asked me to."

"Mai did? Why would she—"

"Are you so uncomprehending that I _have_ to spell everything out?" Big Boss was positively irritated now. "Fine. Nine days ago, as you supposed, we stopped our 'routine' and childish bickering. The night before that, Mai and I discussed some issues between us. But before Mai called me, she was with someone else. Would you care to guess who it was, Yasuhara-san?" His voice was biting as he uttered the last few words.

* * *

 _She practically dragged him toward the club. When he looked up at the lights bearing its name, he sighed in mock disappointment._

"… _It's not a strip club."_

 _Mai just smacked his arm in response, a habit she was rapidly developing thanks to Matsuzaki-san. "What're you even saying, Yasu! Of course it's not a strip club. It's the club that uni students are frequenting lately."_

" _Then why did you ask me to go with you?" he groaned teasingly._

 _Under the neon lights he barely registered the pink that washed over her face. "I told you already, Yasu. I may be wearing four-inch heels and a kind of a slutty dress so I could catch someone's eye, but I'm not going home with anyone but you," she replied seriously._

 _He returned her gaze before letting his eyes scrutinize her: shoulder-length brown hair, blushing face, sparkly black dress that accentuated her curves beautifully and ended halfway down her thighs, black shiny pumps in which she tried not to trip. He took his phone from his pocket to take a full-body picture with the club's name in the background. "Milestone unlocked: Mai's first nightclub." The phone's flash sparked twice. "Man, Big Boss should see this…" He saw her frown, so he tried again. "By the way, Mai, have I told you that you look perfect?"_

 _Her face then brightened with a blush of a deeper shade and a smile as she grabbed his hand. "Not yet, but I was expecting you to. Thanks for going with me, Yasu."_

" _I have to warn you, though. I'm a man-whore, and if I don't get any of your friends to want to sleep with me, I'll get busy with the other clubbers. Hmm… maybe I should aim for the patrons…?" They walked past the bouncers and through the double doors. Then, music, psychedelic lights, and the scent of alcohol flooded their systems._

" _You only act like one. You've never even gotten laid!" she shouted over the electronic tunes the DJ was mixing. "And I don't plan on letting you get laid tonight, Mister Chaperone. Sorry not sorry!" She released his hand when her friends motioned her over. They spent the whole night shout-chatting, dancing, and drinking. And, of course, everyone's attention was on him._

 _ooo_

" _Are you drunk?" he asked as he helped her into a cab._

" _Actually, I don't think so. All that alcohol you guys made me drink on my twentieth must've increased my tolerance." She leaned back in her seat when the cab began to pull away. "I feel so brave and oddly clearheaded right now…" Then, he saw her eyes steel in determination._

" _You're planning something."_

" _More like finally decided to do something."_

 _He had the cab drop her off in front of her apartment complex. "Well, it probably involves Big Boss, so good luck, Mai."_

 _She looked at him thoughtfully and hummed in thanks._

* * *

"It was me." Osamu replied, a bit apologetic. The only times Big Boss talked for long periods of time were during cases, when he was either giving and explaining methodic instructions to the team or elucidating his theories for everyone else to catch on. And although this was, in a sense, a case, it was not the kind he would take enough interest in.

"That's correct. Mai, who acted sober despite appearing to have had an intake of alcohol, called to meet with me. At one point in our discussion, we breached the topic of what to do from that night on. She requested that we stop our 'childish banters', and I accepted it, among many things."

"That's exactly what makes all this absurd, Shibuya-san. Why would Mai want it to stop, when she's in love with you?" Osamu's vexation from his bewilderment was becoming more and more evident.

Big Boss shot Osamu a heated glare. He replied in severe impatience, "You're making things more unbearably idiotic with your presumptions. The entirety of your reasoning is based on the premise that Mai _is_ in love with me. Using that as your principal premise renders your arguments completely and foolishly invalid."

"Stop denying it, Shibuya-san. She's _in love with you_."

"She. Is. _Not._ " Big Boss hissed in extreme bitterness. " _Not anymore._ "

The part-timer gaped at his superior. The president was seething, and he saw a mixture of emotions, together with anger, cloud the other man's eyes before they closed tightly.

A long time passed before he regained his speech. "But-But how could that be possible? Only _you_ could make her happy, Oliver Davis." Osamu replied with a frustration that he did not know he had felt and repressed for a long time.

"—It's simple. That's someone else's job now." The head of SPR opened his eyes and gave his subordinate a piercing gaze. "That's your job now."

The subordinate took a shaky breath and laughed miserably. "Please don't ridicule me."

Big Boss cast his eyes to the half-finished and now cooled tea that Mai had made before she left. Then, he said silently, not unlike a sorrowful whisper, "Please don't be the idiot that I was, Yasuhara Osamu."

"Shibu—!"

"Get out before I fire you for acting like an idiot."

Still at a loss and in shock, Osamu stood up, gathered his things, and headed for the exit. As he closed the office door, he saw Big Boss slowly lift the teacup to drink the last dregs of the cold tea.

* * *

 **Disclaimer:** I don't own Ghost Hunt or any of its characters.


	8. Suspect: Mai Taniyama

**Author's Note:** We've reached the last chapter of _Paradigm Shift_! :D Thank you so much for reading, following, faving, and reviewing—for giving this fic and this pairing a chance. I originally posted this back in 2014 but deleted it due to my massive insecurities. Almost three years later and with my sister's persuasion, I reposted it, and I'm glad that even I gave it another chance. :) So without further ado, I present Osamu Yasuhara's long-awaited enlightenment.

 **Disclaimer:** I don't own Ghost Hunt or any of its characters.

* * *

" _But instead of relying on her best choice, she chose you. Why you, Yasuhara-san?"_

" _Taniyama-san and Takigawa-san are the only ones who address you with a nickname.… But only Taniyama-san is addressed by first name."_

" _No—I'm pretty sure you'd already gotten a grasp of what all this is about, just that when you realized where it was going you may have automatically and subconsciously dismissed it as impossible."_

" _You're the one who_ refuses _to see it."_

" _There's nothing to be sorry for."_

" _That's your job now.… Please don't be the idiot that I was, Yasuhara Osamu."_

On his way to fetch Mai in her apartment, he realized that this was not so much an investigation as one of those Connect the Numbered Dots pages in a children's activity book. And he felt less like a detective and much more like a child who did not want to connect them by number because the picture he would see was something he had never seen before. But now, the dots were connecting by themselves, and he was barely capable of denying the reality of the image that was gradually taking shape.

As a last attempt to resist the materializing truth, he decided to confront the one who turned out to be the only suspect in this case, to make her confirm that everyone else's accounts were wrong and his analysis was correct, after all.

"Wow, you took so long, Yasu! Naru must've given you an earful. What happened?" Mai, ready to go, opened her door after his first knock.

"It's… a long story. Would you like to hear it?" he returned quietly.

"Of course, but—Yasu, are you okay?" She frowned in concern. "Wanna talk about it inside? Let's just order something."

"Yeah." At his reply, she opened the door wider to let him into her apartment. He sat down by the low table and watched Mai bustle around her kitchen, get the kettle boiling on the stove, phone a pizza place nearby, go back to the kitchen, and prepare tea. She acted as she always did, just as she had three years ago and even when they first met in his senior year in high school. She was still bursting with energy and life. She still simply smiled at him when she noticed him staring at her.

If… _If_ what the other members of the SPR team had implied were true, she never gave anything away. _If_ what they had quite eagerly suggested were true, exactly when did she…?

"Here." Mai offered a cup of tea, which he gratefully accepted, and sat beside him. "You're really quiet, Yasu. Oh, now that I look at you properly, you're a little pale, too. Are you sick?" She held a hand against his forehead to check his temperature. "Doesn't seem like it, though." He continued staring at her. "What? Are you gonna talk or are we just gonna play a staring game? Which you'll win, by the way."

He began hesitantly, "I discussed some… matters with Big Boss. No, actually, with everyone."

"Uh huh." She crossed her forearms on the table and rested her head on them. "And what're these 'some matters' that you talked to them about?"

"Matters involving my investigation."

She raised her eyebrows. "Investigation?"

"Investigation of the change between you and Big Boss."

Mai sat up. Her eyes narrowed as she said very slowly, "Yasu, you might want to begin explaining from the very, very beginning."

A minute passed before he took a deep but slightly shaky breath. "…Nine days ago, something changed between you and Big Boss. I've been trying to look into what happened between you two because it's worrying everyone, though everyone else seemed to be less bothered by it after a day. Well, it still worries me greatly. That's why I held my own investigation."

She visibly and audibly swallowed hard. "So what'd you find out?"

"All the information needed to totally break down my theory."

"Which is?"

"That you and Big Boss have finally reached a stage that's closer to dating."

She released a long, amused laugh before replying, "Wow, really, Yasu? That was the theory you created using _evidence_ and _witness statements_? Did you tell Naru? I wish I was there to see his reaction!"

He looked at her disapprovingly. "He called me an idiot." She bent over in laughter. "But he was gracious enough to point my reasoning to what appears to be the right direction, which is very hard to accept and still seems wrong to me."

Mai, still bent over, had her hair covering her face, but it was clear that she had stopped laughing. "What did he say?" He barely heard her utter the next words: "That _idiot_."

Lowering his head and readjusting his spectacles, he answered, "That you two had a talk after I dropped you off that night we went clubbing. That you had agreed to stop fighting over the smallest things. And he implied that—" he stopped, unable to continue.

"That what?" she urged him on softly.

He directed his gaze at her. "That you're… in love with me."

She raised her head and turned to him. "…And why do you find it unacceptable and wrong?"

"Because you're in love with Big Boss, Mai, and Big Boss is obviously not me."

"You think it's impossible for me to fall in love with you?" There was a hardness in her voice that he rarely heard, and the instances in which she used that tone were the only few times with her that he wished he did not have to remember.

"It's hard to love someone else when you've already fallen in love with the most amazing person you'll ever meet." He forced himself to transform the thoughts in his mind into audible, sensible words, but he realized that he had done a mediocre job when he saw Mai's face crumple despite her efforts to prevent it from doing so.

"But I fell in love with you anyway."

An overwhelming silence fell over them. He heard the staccato ticking of her clock, each tick a countdown to the bomb he no longer had time and energy to defuse.

"Did you really fall in love with _me_ , or did you choose me because you were going nowhere with _Oliver Davis_?" he asked silently. Mai let out a horrified gasp.

"… _I can't believe you would ask that_." Her voice was so dreadfully pained that he cringed at his own cruelty.

Still, he did not apologize, and she did not ask him to. Neither of them spoke or moved for a long time. They were both painfully aware that this was the turning point of their relationship, and that they were balancing on a tightrope in an effort to keep everything from falling apart.

Eventually, Mai broke the silence. "You strongly believe in your detective skills, don't you?"

"Quite strongly, though I'm seriously starting to question it now."

"Just humor me."

"Okay."

"Since you're 'investigating' what went on between me and Naru, let's say that you're a detective and I'm your primary suspect. Right now, I'm detained in a dim interrogation room, with a single light bulb hanging above the table separating us."

"That's visual," he said as a smile threatened to spread on his lips.

"Shhh…" she hushed him, but there was mild mirth in her voice. "Just let me continue. Now I'm going to tell you my alibi and explain my actions in certain important events. I'll try to prove to you that I'm guilty. Got it?"

"Yeah. Well then…" He coughed to imitate the voice of a police detective. "Taniyama-san, what were you doing on the night of the thirteenth of this month?"

"I was with you in a nightclub having the time of my life, Yasuhara-keiji. You could verify that with yourself."

"It's been verified; it's true." He nodded. "We then called a cab to get you to your apartment complex safely and me to mine. What happened after?"

"Remember how I told you I was feeling brave and clearheaded that night? Well, that night, I finally had the courage to confess everything to Naru, so I told myself why not and called him. And then we talked about many things: about how I loved him and not Gene… about how I really loved him romantically for years…"

She breathed deeply before she spoke again. "…about how I still love him now, only in a different way… about how I could and would love to be like his nagging little sister—of course not as Gene's replacement… about how I'd appreciate it if we stopped pretending to be so infuriated by the little things the other does… about how I'd fallen in love with you." Mai smiled wistfully.

He averted his gaze. "…It's not enough evidence, Taniyama-san."

"I know.

"Keiji-san, I'm pretty sure I've also been acting a little strangely for a few years now."

"My… would you like to expound on that?"

"I actually began to have a light crush on you when you were tutoring me for my entrance exams. At that time I couldn't help looking at you and thinking to myself, _'Hey, he's really kind and kind of handsome. His girlfriend will be lucky to have him.'_ "

A laugh escaped his mouth before he could stop it. She simply shrugged.

"Also, I never told you I was trying to get into Todai before graduation, did I? I wanted to surprise all of you and show that I can be smart, too. Besides, it seemed like you were having fun in your uni, not to mention that you became more… uh… interesting and open, I guess? Oh, and promiscuous too.

"And then when I passed my exams, I tried to ask you out to lunch or dinner, but you advised—as a _dirty old man_ —that we should celebrate with everyone. My first attempt to buy you a meal as your friend was rejected. It was embarrassing, you know? But I got away with something better because I got to call you Yasu and you began to call me Mai. Plus that flirtation at the end of the call…" Mai sighed. "I seriously didn't know what I was getting into that time, huh. I think that was the time that my light crush became a real one."

"What can I say?" It was his turn to shrug.

She rolled her eyes at him. "Oh, please. Anyway, what's next? Oh…" Her face pinked.

"Oh?" he repeated.

"Remember that time when I was really stressed out with finals on my very first semester in Todai?"

He chuckled and answered, "Of course I do. You had me terribly concerned about your health. And your baby's." She smacked his arm in mild irritation.

"Well, after I passed my finals—with flying colors, thanks to you—" He bowed. "—I really got to thinking about you. You were so kind and helpful to me, sometimes—okay, maybe most of the time going out of your way to get to my side when I needed you. So I wondered if you were always like that to all your other friends. I tried imagining you doing all that for someone else, and I disliked the idea. I realized quickly that maybe it's because I was your best friend after all, but I spent days thinking why I was too much of a possessive best friend. I actually asked a mutual friend, you know? He said it may be because I was starting to like you. Then I spent nights thinking whether I'd really started liking you. I wasn't able to answer myself.

"But I found my answer finally after my birthday 'party'." She held out the index and middle fingers of both hands and wiggled them. "When I woke up on my bed, sober again, the next day, I was wracked with desperation. Why did I have to be your best friend? Why didn't you meet me before Naru did? Why was I even thinking about these things? Why was I so frustrated? I became motionless when the answer slapped me in the face. Now that I think about it, it was really obvious. But I fell so fast I guess my eyes were still blinded and adjusting to the new light." She paused and stood up to replace the tea that had grown cold.

He remained quiet during Mai's soliloquy. Her words left the makeshift conclusion he thought he had built sturdily in shambles. Conclusive evidence and an incriminating confession had already been presented to him. The dots had been connected, and the image that they formed was too real to deny.

But he still found it incredible. Unknowingly, he voiced out his thoughts. "How could this happen? You've always been in love with Big Boss, and I couldn't even compare to him."

"I told you and everyone else before, didn't I?" She set the refilled cups on the table, sat, and gazed into his eyes. "Those who always chose to be there with me are more important than those who didn't. And to be honest, now that we're almost always together, I can barely imagine how I'll act normally without you." Then, she asked expectantly, "So, did I convince you of my guilt, Keiji-san?"

They stared at each other for a bit longer, and then he smiled. "Not yet, Taniyama-san." He leaned forward, decreasing the distance between their faces. She turned bright red. "But I'll give you another chance."

Mai parted her lips as she retracted her head slightly. He waited. She slammed her forehead onto his.

"Well? Did that finally shift your paradigm, Yasuhara-keiji?" she asked condescendingly, alleviating the pain on her forehead with a soothing rub. He laughed at her silliness, and she laughed at the way he flinched when she poked the point of impact on his forehead.

He fixed the position of his glasses on his nose and looked at her. "Why, indeed it did, Taniyama-san! Very drastically so.

"I'm profoundly and genuinely in love with you," Osamu confessed feelingly.

She gasped at the unprecedented and direct profession and gaped at him for a long time.

Then, slowly, Mai beamed.

Osamu Yasuhara believed himself to be a talented detective: he can study a case from different angles and can formulate a conclusion that is consistent with all evidence and accounted for by valid statements. However, there was one case that he thought he cannot solve. That he was afraid to solve.

But he did, with the help of the suspect herself.

As she threw herself at him to engage him in a tight embrace, he grinned in satisfaction and happiness. There was only one thought on his mind.

 _Case closed_.


End file.
